Machine for winding wire in making prestressed bevel-end concrete pipe



Sept. 4, 1962 E HUCK 3 G. MACHINE FOR WINDING WIRE IN MAKING PRESTRESSED BEVEL-END CONCRETE PIPE Filed April 28, 1958 2 Sheets-Sheet 1 INVENTOR.

606 E H/oe Arrae wrrs.

Sept- 4, 1962 G. E. HUCK 3,052,266

MACHINE FOR WINDING WIRE IN MAKING PRESTRESSED BEVEL-END CONCRETE PIPE Filed April 2a, 1958 2 Sheets-Sheet 2 5 .EMO

INVENTOR.

61096; E HP/Qe 71 v/w/w 3,052,266 MACHINE FOR WINDING WIRE IN MAKING PRE- STRESSED IBEVEL-lEND CGNCRETE FEE George E. Huelr, Fullerton, Calif assignor to American Pipe and onstruction (10., South Gate, Calif, a corporation of Delaware Filed Apr. 28, 1958, Ser. No. 731,402 4 Claims. (Cl. 138-176) This invention has to do generally with the manufacture of prestressed concrete pipe wherein wire is wound under tension around the concrete body of the pipe and secured thereto to thereby subject the concrete to a compressive force.

In the manufacture of prestressed concrete pipe it is often necessary to make bevel end pipe wherein one end of the pipe is oblique or inclined with respect to a plane normal to the longitudinal axis of the pipe. Since the wrapping of the pipe body is done by wire feed apparatus which advances along the pipe body at a uniform rate While the pipe is rotated, a regular or uniform helical winding is applied. This winding, of course, cannot be carried beyond the inner limit of the beveled end portion of the pipe body. Consequently it has been customary to complete the helical winding adjacent the beveled end at the short side of the pipe and then provide makeshift means for reinforcing the remainder of the pipe from there to the end. This is objectionable since the beveled end portion of the pipe is then not stressed in the same manner as the remainder of the pipe.

Therefore, it is an object of my invention to provide novel means for winding reinforcement wire around a pipe body having a beveled end in a manner to prestress the entire pipe body from end to end, including the portion which is at the beveled end thereof.

Another object is to provide a novel method of Wrapping such a beveled-end type of concrete body or the like so that the wrapping may be carried out from end to end of the body.

Still another object is to provide a novel pipe wrapping and wire feeding mechanism whereby the portion of the device through which the wire is fed can be cyclically non-uniformly advanced along the pipe in synchronism and coordination with the rotation of the pipe to provide a unique winding pattern of modified helical form.

More particularly, it is an object to provide novel means for oscillating an arm or other member in timed relation with the operation or movement of a related object whereby the oscillating movement may be progressively increased, or otherwise varied, in accordance with a predetermined pattern.

Still another object is to provide a novel cam and lever means for use as a part of a servomechanism apparatus.

These and other objects will be apparent from the drawings and the following description. Referring to the drawings:

FIG. 1 is an elevation View, somewhat diagrammatical, of apparatus embodying the invention;

FIG. 2 is a diagrammatic representation of the bevel end portion of a pipe embodying the invention;

FIG. 3 is a graphical representation of a portion of the wrapping and of the oscillations of the wire feed means;

FIG. 4 is an enlarged fragmentary elevational view of the principal working parts of the apparatus of FIG. 1 which embody the invention;

FIG. 5 is a fragmentary sectional plan view on line 5-5 of FIG. 4; and

FIG. 6 is a schematic view of the operative relation between certain of the principal parts of the invention.

$352,255 Patented Sept. 4, 1962 More particularly describing the invention, numeral 11 designates a concrete pipe body which is shown positioned upright upon a rotary table 12 and which is mounted for rotation upon a base 13; motor 14, worm 15 and ring gear 16 being shown as the means for rotating the table. It is to be noted that the upper end 11 of the pipe body is disposed in a plane which is oblique or inclined with reference to a plane normal to the longitudinal axis of the pipe body.

The pipe body is shown in FIG. 1 partially wrapped by reinforcing wire 18 which has been applied by a wire feed means generally designated 20. The feed means includes a carriage 21 which is mounted in any suitable manner for vertical movement along an upright supporting structure 22 which is parallel to the axis of rotation of the pipe body. The carriage may be moved vertically upon the structure 22 by means of a motor-driven pinion 23 which engages a rack 24 upon the support. The carriage supports a wire supply reel 26 and may carry any desired conventional means (not shown) for restrainin the wire as it is pulled from the reel by the rotating pipe body. It will be apparent that in the operation of the device, the carriage is advanced along the support and, as the pipe body 11 is rotated, wire 18 is fed or payed out under tension to the pipe body in consequence of which a uniform helical wrapping is formed about the pipe body.

The wire feed means includes a Wire feed arm designated 30 which is pivotally mounted at 31 upon a frame structure 32 forming part of the carriage 20. The arm is provided with a pair of guide rollers 33 and 34 at its outer end through which the Wire feeds. A bracket arm 36 integral with the arm supports a fluid motor shown as a fluid ram element 38. The latter includes the cylinder 39 and a piston therein (not shown) having a projecting piston rod 40 which is pivotally mounted at 41 upon the frame structure 32 of the carriage. It will be obvious that with this construction as the ram 38 expands longitudinally the arm 30 will move downwardly from its normal horizontal position in which it is shown.

In order to wind the wire about the beveled end portion of the pipe body I form a modified helical wrapping about the pipe from a region spaced a substantial distance from the beveled end of the pipe body to the beveled end. In doing this, I prefer to first determine the length of the beveled end portion of the pipe, this distance being designated as d in FIG. 2. I then begin wrapping the pipe with a modtfied helical winding from a point along the pipe spaced from the extreme end of the beveled end of the pipe a distance arbitrarily chosen as several times d, designated xd in FIG. 2. Thus the pipe body is wrapped in the regular manner so as to produce a uniform helical winding throughout the portion 42 of the pipe body up to the chosen point, designated 43. I then tilt the turns of the helical winding progressively as they are applied, maintaining the same spacing between turns along the long side of the pipe and decreasing the spacing along the short side by the proportion required in order to evenly space the turns along the short side and produce the modified helical winding throughout the section 45 of the pipe body. This may be accomplished by the apparatus disclosed by causing the wire feed arm to oscillate in synchronisrn with the rotation of the pipe body in a manner such that the arm dips below its normal horizontal position and is at its greatest amplitude or lowest point coincident with the time that the wire therefrom contacts the shortest side of the pipe. The amplitude of oscillation of the arm is progressively increased by the amount of the amplitude of the first oscillation upon succeeding oscillations. This is shown graphically in FIG. 3. It is to be understood that the carriage is advanced uniformly as the arm is oscillated.

Referring to FIGS. 4, 5, and 6, in order to actuate the wire feed arm so that its oscillations progressively in crease in amplitude, I provide a cam which is splined to a shaft 51 to enable the cam to be advanced axially therealong. T he shaft is journaled in brackets 52 and 5'3 which extend outwardly from a base plate 54 secured to a section 55 of the carriage frame by bolts 56. The shaft 51 is driven in synchronism with the rotary table 12 by a selsyn motor 60. The latter is electrically connected in a conventional manner to a second selsyn motor, 61, which is driven by the table at the same rate as the table.

For advancing the cam '50 axially, I provide a screw shaft 64 journaled at 65 and 66 upon portions of the carriage 67 and in the brackets 52, 53 heretofore referred to. A worm or screw thread 6 is formed on the shaft and this is received in an internally threaded yoke body 78 having a yoke element 71. The latter is received in a reduced portion 72 of the cam.

Shaft 64 is driven in synchronism with the means which advances the carriage in order that the cam will be advanced throughout its length as the carriage traverses the distance xd (FIG. 2). The drive means may include a clutch member 74 and a drive connection 75 between the clutch and the pinion 23 heretofore referred to. The shaft is shown provided with a sprocket wheel 78 which may be connected by a chain (not shown) through other drive means to the pinion. The latter is driven by a motor 80.

I provide a cam follower lever 82 which is pivotally suspended at 83 (FIG. 4) from an element 85 carried on the bracket arm 36 of arm 30. The lever normally rides against the periphery of the cam as shown in FIGS. 4 and 5, and the lower portion of the arm is provided with a head 87 which is adapted to contact the actuating pin 88 of a servovalve 90. The latter is mounted on arm 30 and is connected between the ram 38 and a source of fluid under pressure by means of conduits $1, 93, 94, and 95.

In the operation of the apparatus, at the appropriate time, clutch 74 is engaged (manually or automatically) to drive the cam axially. As the cam rotates in synchronism with the pipe body being wrapped, the cam moves axially and rotatively past the cam lever to actuate the same. The cam is so shaped as to progressively increase the movement of the lever, and hence movement of Wire feed arm 30, in accordance with the predetermined pat tern. As the cam rotates, it moves the lever 82 to the left as viewed in FIG. 4. The lever in turn actuates the servovalve 90 which supplies fluid to the ram 38, causing the same to expand and move the arm 30 downwardly. In this connection it should be pointed out that the servovalve 90 is preferably internally spring-biased in a direction to move its actuating pin 88 outwardly. It may be assumed that when the pin 88 of the valve is to the right of the position in which it is shown in FIG. 4, fluid is supplied to ram 38 in a manner to contract the ram and that when the valve pin is moved to the left of the position in which it is shown fluid is supplied to the ram in a manner to expand the ram. As the arm 30 moves downwardly the point of pivotal support of the cam lever 82 moves arcuately to the left (FIG. 4) permitting the lever to incline rearwardly at its lower end under the influence of the spring-biased valve pin 88 with the result that the latter returns to its original position. This sequence is repeated as the cam rotates and the arm 36) thus moves downwardly in a series of small movement until the high point of the cam has passed. The mechanism then permits the arm to return to its original position by reason of the arm being allowed to retract under the influence of the cam 50 and the spring-biased valve pin 88.

As previously indicated, the clutch 74 may be operated manually or automatically. In either case, for convenience, clutch 74 may be electrically actuated of the solenoid type, as indicated in FIG. 6 where the solenoid portion has been designated 748. The solenoid circuit may be automatically energized by a switch carried on the carriage which engages and is actuated by a trip 1M mounted on the support 22. at the required height.

Although I have illustrated and described a preferred form of my invention, I contemplate that various changes and modifications can be made therein without departing from the invention, the scope of which is indicated by the following claims. For example, if desired, I may first wrap the beveled end portion of the pipe or other object and subsequently wrap the remainder. This can be done by causing the carriage to traverse the object to be wrapped in a reverse direction from that previously described and operating the cam accordingly.

1 claim:

1. The method of reinforcing a cylindrical body terminating in a beveled end disposed in a plane oblique to the longitudinal axis of the body which comprises wrapping wire about the body by rotating the body and simultaneously feeding wire under tension to the body and advancing the feed point of the wire longitudinally of the body at a uniform rate until said body has been wrapped to a point substantially short of said beveled end, and continuing to rotate said body and continuing to feed wire under tension to the body while advancing said wire longitudinally of the body at a non-uniform rate with a varying cyclical oscillating movement of increasing magnitude in timed relation to the rotation of the body and coordinated with the short and long sides of the body whereby to decrease the spacing between turns of the wire on the short side of the body and maintained the original spacing on the long side thereof.

2.. A prestressed concrete pipe comprising a cylindrical body of concrete terminating at one end in a beveled end disposed in a plane oblique to the longitudinal axis of the body, and a Wrapping of wire under tension around said body, said wrapping being in the form of a regular helix up to a region substantially short of said beveled end, and being in the form of a modified helix therebeyond, said modified helix having turns relatively closely spaced on the short side of the pipe and more widely spaced on the long side of the pipe.

3. The method of making a prestressed concrete body terminating in a beveled end portion comprising wrapping wire in tension about the body by producing relative rotation between the body and a wire feed means and simultaneously feeding wire under tension to the body from the feed means while producing relative movement between the body and the feed means in a manner to advance the feed means longitudinally of the body at a uniform rate until said body has been wrapped to a region substantially short of said beveled end portion, and thereafter, continuing to produce relative rotation between the body and the wire feed means While producing relative movement between said body and said feed means in a manner to advance the feed means at a non-uniform rate and produce a varying cyclical oscillating movement of increasing magnitude between the body and feed means in timed relation to the relative rotation of the body and in coordination with the short and long sides thereof whereby to decrease the spacing between turns of the wire on the short side of the body and maintain the original spacing on the long side thereof.

4. A prestressed concrete pipe comprising a cylindrical body of concrete terminating at one end in a beveled end disposed in a plane oblique to the longitudinal axis of the body, and a wrapping of wire under tension around said body, said wrapping being in the form of a regular helix up to a region substantially short of said beveled end, and being in the form of a modified helix therebeyond, said modified helix having turns relatively closely spaced on the short side of the pipe and more widely spaced on the long side of the pipe, the turns of said wrapping forming the modified helix being evenly spaced from end to end of the pipe along its peripheral region of greatest spaced on the peripheral region opposite thereto.

References Cited in the file of this patent UNITED STATES PATENTS Miller Mar. 25, 1941 Hopkins Aug. 24, 1943 Kitselman Oct. 26, 1948 Hirsh Aug. 29, 1950 6 Hirsh Feb. 3, 1953 Kennedy June 21, 1955 Peckworth Sept. 13, 1955 Wread Dec. 25, 1956 Breguet Apr. 2, 1957 FOREIGN PATENTS Great Britain July 13, 1855 Austria Feb. 25, 1949 Great Britain Mar. 14, 1956 

